Heretofore there have been many, many different types of caulking guns and other similar dispensers provided and made and sold commercially in large quantities for dispensing grease, sealing materials, caulking material, etc. These guns are usually adapted to receive a conventional caulking or grease cylinder, etc. therein and to apply pressure in a controlled manner to the plastic to be expelled. Normally, a pressure piston or screw controlled plunger is provided in the gun or dispenser to force the contents of a caulking cylinder or grease container etc. therefrom.
Typical patents on metal caulking guns as made and sold in large quantities heretofore would include U.S. Pat. Nos. 2,720,345 and 2,801,775. These caulking guns have included some type of a ratchet and rack gear connection between a control piston rod and propelling lever mechanism. Some type of a control level is usually pivotally secured to a handle member or other frame unit to move the control piston rod forwardly by increments for expelling caulking material from an associated caulking cartridge.
It is desired to make a caulking gun wherein the cost thereof can be reduced and the weight and size of the gun can be also reduced. Furthermore, it is desirable to expel the contents of a caulking cylinder or the like gradually and continuously from the associated gun rather than by the propelling or extrusion by increments as provided by a ratchet type squeezing action or pressure exerted upon a caulking cartridge and its contents.
In view of the foregoing, it is the general object of the present invention to provide an improved plastic caulking gun of reduced weight and cost; a dispenser that is of a design that can be made from suitable plastic material; and to provide a dispenser wherein the contents of a caulking cartridge or similar member can be continuously uniformly expelled by a drive screw action.
Another object of the invention is to provide a multi-purpose dispenser, such as a caulking gun, as outlined hereinabove and wherein the caulking gun permits rapid retraction of the control or pressure screw of the caulking gun when it is desired to retract the control piston and adapt the gun for receipt of a filled caulking cartridge.
Yet another object of the invention is to simplify the construction of a caulking gun and to improve the ease of operation thereof, and to reduce the time required in use of caulking guns and the refilling of a caulking gun with a new cartridge.
Yet another object of the invention is to provide a relatively simple engagement between a caulking gun frame and a control or pressure drive screw in the caulking gun so as to permit the engagement and disengagement of this drive screw re the frame in an easily controlled rapid manner.
The foregoing and other objects and advantages of the present invention will be made more apparent as the invention proceeds.